Child Support Deviation Factors by State (2026)
The guideline amount is a presumption, not a ceiling. Which states allow judges to deviate, the written-findings requirement, and the most common deviation factors — special needs, extraordinary expenses, parenting time, and more.
Every state starts from a presumptive guideline number — the amount the calculator produces. But in every state, a court can set a different number if applying the guidelines would be unjust or inappropriate. The catch: most states require specific written findings explaining why. Understanding the deviation rules tells you whether your case has room to move, and what a court will want to see.
The written-findings requirement
Deviations are the exception, not the rule. States uniformly require the court to state in writing: (1) the guideline amount, (2) why that amount would be unjust or inappropriate, (3) the specific facts justifying departure, and (4) why the deviation serves the child’s best interest. Illinois (750 ILCS 5/505, as amended by Public Act 102-0823) and Massachusetts (2025 Guidelines § IV, eff. Dec. 1, 2025) both codify this exact structure. An administrative agency (the state IV-D office) usually cannot apply a deviation it cannot quantify — Ohio requires the deviation to be expressed as a dollar amount or percentage (R.C. 3119.63(B)).
The most common deviation factors
- Child has special medical, physical, or developmental needs (IL, MA, MI, OH)
- Extraordinary educational expenses — tuition, tutoring, special-needs schooling (MI factor 2; IL extracurricular add-ons)
- Extraordinary medical expenditures necessary to preserve life or health of a party or child (IL)
- Parenting-time imbalance — one parent provides substantially more or less than one-third of parenting time (MA; MI factor 15)
- Extraordinary child-care costs that exceed the state average (OH; MI factor 18 when child-care exceeds 50% of base support)
- Gross disparity in living standards between the two households (MA)
- Extraordinary travel or exchange costs for parenting time (MA; OH)
- Significant in-kind contributions — direct payment for lessons, sports, school, or clothing (OH)
- The payor is incarcerated with insufficient resources (MA; MI factor 13 for conviction-related obligations)
- The child has extraordinary income of their own (MI factor 11)
Michigan publishes one of the most detailed lists in the country — roughly seven categories and nineteen numbered factors in the Michigan Child Support Formula Manual (2023 memorandum). The list is not exclusive, and the presence of a factor does not mandate a deviation; it signals the court to look more closely.
What is not a valid reason to deviate
- Great income disparity between parents — Michigan (Burba v. Burba, 461 Mich 637, 2000) holds the formula already accounts for income disparity, so it cannot be reused as a deviation reason
- Lower cost of living in the child’s state — rejected in Michigan’s Teran v. Rittley, 313 Mich App 197 (2015)
- A parent’s voluntary choice to earn less — that triggers imputed income instead
- Informal (unapproved) agreements between parents — courts do not honor them
Above-guideline awards and add-ons
Deviations cut both ways. In addition to lowering support, courts can order add-ons on top of the base: Illinois allows discretionary contributions for school and extracurricular expenses (750 ILCS 5/505(3.6)) and child-care costs prorated by income share (3.7); Massachusetts allows above-guideline orders with findings; Ohio factors in post-secondary expenses a parent already pays (R.C. 3119.23). High-income states cap the base (see the high-income cap hub), and courts often apply the statutory percentage to income above the cap with findings — which is itself a deviation-style discretionary act.